From the information I could find on that amplifier, it is stable at one ohm and provides 700 W RMS at that resistance. With two four ohm dvc subs you can wire them parallel/parallel for a final load of one ohm.
Hi Hector, if all the wiring is connected properly, you then mite have a problem on the circuit board, or with the subwoofer itself. While its switched off try moving the switches one or two times just in case there is a dry contact. Next would be to take in the unit for an independant bench test before opening the unit. Cheers.